This meta-analysis was conducted to confirm the effects of soy isoflavone supplementation on body weight, fasting glucose, and insulin level in non-Asian postmenopausal women. PubMed, EMBASE, and Cochrane databases up to October 2010 were searched for randomized controlled trials; 9 studies with 528 participants for body weight, 11 studies with 1182 participants for fasting glucose, and 11 studies with 1142 participants for fasting insulin were included. Significant reductions were found in body weight (95% CI -0.895 to -0.134), glucose level (95% CI -0.344 to -0.033), and fasting insulin level (95% CI -1.721 to -0.159) with soy isoflavone supplementation compared to placebo. Furthermore, shorter duration of isoflavone supplementation (<6 mo) reduced body weight (P = 0.009) and longer duration of supplementation (≥6 mo) reduced blood glucose (P = 0.001). Greater weight loss reduction was observed in the lower dose subgroup (< 100 mg). Moreover, supplementation was more effective to reduce body weight and fasting insulin level in normal weight (BMI < 30) than obese (BMI ≥ 30) women. Therefore, soy isoflavone supplementation could be beneficial for body weight reduction, glucose, and insulin control in post-menopausal women. Nutrition. 2012 Aug 1. PMID: 22858192
